Parametric design

With Pro/Engineer (Pro-E)Parametric Technology Corporation

(ptc)

What is Pro/Engineer?

• 3D solid modeling and design program• Fundamental proE concepts:

• Feature-based modeling• Associative• Parametric

What does feature-based mean?

• Feature-based modeling means you start with simple basic features and then add more features

• Part is ‘constructed’ so that its individual features describe the way the geometry should behave - ie a cut ‘knows’ its shape and location and the fact it has negative volume

Associative

Parametric Design

• Each feature you give the part is a parameter which can be changed

• Parent-child relations are important to understand

Implicit vs. Explicit Relationships

• Implicit - new geometry or feature is sketched/dimensioned based on some existing part

• Explicit - new geometry is defined mathematically by the user, ie any number of spoke holes in a bike rim are all equally distant to each other

What is parametric modeling used for?

• CAD• Analysis of design concepts• Improvement of rapid prototyping process• Reduced iterations and increased optimization• Simulation

• Actual performance of design• FEA (finite element analysis)• Simulated performance under extreme conditions safely

- fire, earthquake, max. loads

Where is ProE available from?

• Student version is available from ptc website or bookstore, etc.

• Student version also available in EBUII 239 and 203 computer labs• Note- student version and full version

incompatible!

Some examples…

Examples…

Harley Davidson Design

Prosthetic feet

Lotus Elise design (rendered image)

Gas Turbine design - try this in AutoCAD…and test your sanity

Examples…

Now to proE…

Pro-E Assembler

Methods of Assembly-parametric assembly-)assign the position of a part relative to the base part or subassembly-nonparametric assembly-)package option in component menu, and change relative position-create parts directly in the assembler

How to think about assembling

• Bottom up assembly design • Existing parts are assembled to your

specifications• Top down assembly design

• Create parts in the assembler relative to others• Combination

• Assemblies can be edited for organization, placement, and can even become subassemblies in a larger assembly

Hints for successful sessions

• Know how to fix your mistakes! If some dimension is wrong or a feature is not as wished, change it! This is a feature-based program, so all features remain editable.

• Apply your understandings of other three dimensional programs and even art to creating models in proE- you'll find you can pick up more about proE faster that way.

• Always make a folder for your new parts or assemblies then change your working directory to that, as the previous models tend to mount up. If you don't change the directory, the root directory of your hard drive will soon become a big group of blank icons.

More hints

• Above all...stay calm. The more angry you get, the less well pro-E will work for you...trust me. If something isn't working, take a break, go get a glass of water, a coffee, go lie down somewhere, or meditate.

References

• The web• Many online tutorials, examples, resources• www.ptc.com/community/

• Books• Bookstore carries training books• Books by Louis Gary Lamit such as Pro/Engineer 2000i^2• Professors doing research with ProE/ProMechanica

• Practice, practice, practice!!!• Model your entire home and prove to your significant other

that that new couch really will fit• Warning! The model is never the true system!• Model your car, your bike, your bird, etc.

End of Talk

Questions?

Appendix

What is a Datum?•Points, planes, axes, coord systems, curves

Why use Datums?